Robotic Materials

An Easy‐to‐Implement Toolkit to Create Versatile and High‐Performance HASEL Actuators for Untethered Soft Robots

2019

Article

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For soft robots to have ubiquitous adoption in practical applications they require soft actuators that provide well-rounded actuation performance that parallels natural muscle while being inexpensive and easily fabricated. This manuscript introduces a toolkit to rapidly prototype, manufacture, test, and power various designs of hydraulically amplified self-healing electrostatic (HASEL) actuators with muscle-like performance that achieve all three basic modes of actuation (expansion, contraction, and rotation). This toolkit utilizes easy-to-implement methods, inexpensive fabrication tools, commodity materials, and off-the-shelf high-voltage electronics thereby enabling a wide audience to explore HASEL technology. Remarkably, the actuators created from this easy-to-implement toolkit achieve linear strains exceeding 100%, a specific power greater than 150 W kg−1 , and ≈20% strain at frequencies above 100 Hz. This combination of large strain, extreme speed, and high specific power yields soft actuators that jump without power-amplifying mechanisms. Additionally, an efficient fabrication technique is introduced for modular designs of HASEL actuators, which is used to develop soft robotic devices driven by portable electronics. Inspired by the versatility of elephant trunks, the above capabilities are combined to create an untethered continuum robot for grasping and manipulating delicate objects, highlighting the wide potential of the introduced methods for soft robots with increasing sophistication.

Author(s): Shane K Mitchell and Xingrui Wang and Eric Acome and Trent Martin and Khoi Ly and Nicholas Kellaris and Vidyacharan Gopaluni Venkata and Christoph Keplinger
Journal: Advanced Science
Volume: 6
Number (issue): 14
Pages: 1900178
Year: 2019
Month: June
Day: 11
Department(s): Robotic Materials
Bibtex Type: Article (article)
Paper Type: Journal
DOI: 10.1002/advs.201900178
URL: https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.201900178
Additional (custom) Fields:
acknowledgements: X.W. and E.A. contributed equally to this work. The authors would like to thank C. Chase-Markopoulou for her CAD drawings of donut HASEL actuators and M. King for fabricating initial prototypes of curling HASEL actuators. The authors would like to thank T. G. Morrissey for his expertise and guidance pertaining to the efficiency experiments. The authors would also like to thank S. Humbert for the use of highspeed camera equipment (Phantom v710 and high-power tungsten flood lights). This work was partially supported by start-up funds from the University of Colorado Boulder. S.K.M. was supported through the NASA Innovative Advanced Concepts program (No. 80NSSC18K0962). X.W. acknowledges financial support from the Joint Doctoral Training Program (No. 201706260025) at the China Scholarship Council. E.A. was supported by Toyota Research Institute North America and a Research Innovation Fellowship from the University of Colorado Boulder, Department of Mechanical Engineering. T.M. acknowledges financial support from the Undergraduate Research Opportunity Program at the University of Colorado Boulder. K.L. and N.K. were supported through the NSF Cyber-Physical Systems grant No. 1739452. C.K. received partial financial support through a Packard Fellowship from The David and Lucile Packard Foundation. The authors also acknowledge funding from the Army Research Office (Grant No. W911NF-18-1-0203), which was used to purchase laboratory equipment to characterize and fabricate actuators.
conflict_of_interest: S.K.M., E.A., N.K., and C.K. are listed as inventors on a U.S. provisional patent application (62/813266) and PCT applications (PCT/ US2018/023797 and PCT/US19/020568) which cover fundamentals and basic designs of HASEL actuators as well as methods of fabricating and stacking actuators. S.K.M., E.A., N.K., and C.K. are co-founders of Artimus Robotics, a start-up company commercializing HASEL actuators.

BibTex 

@article{Keplinger19-AS-SoftRobots,
  title = {An Easy‐to‐Implement Toolkit to Create Versatile and High‐Performance HASEL Actuators for Untethered Soft Robots},
  author = {Mitchell, Shane K and Wang, Xingrui and Acome, Eric and Martin, Trent and Ly, Khoi and Kellaris, Nicholas and Venkata, Vidyacharan Gopaluni and Keplinger, Christoph},
  journal = {Advanced Science},
  volume = {6},
  number = {14},
  pages = {1900178},
  month = jun,
  year = {2019},
  doi = {10.1002/advs.201900178},
  url = {https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.201900178},
  month_numeric = {6}
}